Morse code printing system



Dec. 19, 1950 L. A. THOMAS ETAL 2,534,387

MORSE CODE PRINTING SYSTEM Filed Nov. 15, 1946 5 Sheets-Sheet l QN 4%N w Q mmh L. A. THOMAS ET AL MORSE CODE PRINTING SYSTEM 5 Sheets-Sheet 2 Filed Nov. l5, 1946 BY .7H/W55 fici/e ATTORNEY De- 19, 1950 A. THOMAS ET Al. 2,534,387

MORSE CODE PRINTING SYSTEM Filed Nov. 15, 194e 5 sheets-sheet s Dec- 19, 1950 A. THOMAS ET AL 2,534,387

MORSE CODE PRINTING SYSTEM Filed Nov. 15. 1946 5 sheets-sheet 4 6 Fmr/9005554, if

Dec. 19, 1950 l.. A. THOMAS ET AL. 2,534,387

` MORSE CODE PRINTING SYSTEM Filed Nov. 15, 1946 5 sheets-sheet 5 NNN uw mm. wavmm liF Patented Dec. 179, 1.950

UNITED STATES PATENT OFFICE MORSE com: PRINTING SYSTEM Application November 15, 1946, Serial No. 709,992

(C1. FX8- 26) 21 Claims.

This invention relates to electronic circuits for automatically transposing or converting signals or messages from one code into another, and particularly to such circuits for automatically transposing continental Morse telegraphic code signals into equal length printer code signals.

The continental Morse code employs dots and dashes for the various code combinations comprising the letters of the alphabet and symbols. Each dot is equivalent to a single baud or elemental time interval while the dash is equivalent to a 3 baud time interval. The term baud is used herein to refer to a unit of time and is in fact half of a dot cycle, the duration of the baud being determined by the keying speed. The dots and dashes are separated by spaces Whose duration determines whether or not the preceding and succeeding character elements constitute part of a single letter, separate letters or separate Words. A space of 3 bauds duration represents an inter-character or inter-letter space, while a space of 5 or more bauds represents a word space. The characters within a single letter are separated by an intraletter or inter-element space of 1 baud duration. The letters and symbols of the Morse code are generally made up of unequal length code combinations of dots and/or dashes. The printer code on the other hand employs ecual length code l"ornhinations for every letter of the alphabet and for every symbol. The code combinations of a printer code are composed of a plurality of equal length units or elen ments. The most common printer code employs 5 units for every code combination, while other printer codes employ 6 units. or seven units or more for each code combination.

Heretofore. in retransmitting intelligence in printer code from received continental Morse code signals, it has been the general practice ,to copy the received signal aurally or record the received Signals on an inked tape, then transcribe the signals on a typewriter, and thereafter manually periorate a tape by means of a kevboard tape perforator. or operate a Teletype printer machine. Such an arrangement requires one or more operators, thus increasing the cost of operation, and in addition, is likely to introduce errors due to the human eouation.

It is known that to translate Morse code signals into printer code signals by purely mechanical apparatus, requires apparatus that is both complicated and costly. Further, such known mechanical signal code converting arrangement requires a reperforated Morse tape rfor its controlling means.

An object of the present invention is to provide an improved method of and means for automatically producing perforated telegraphic printer code tace directly from continental Morse code telegraphic signals.

Another object of the invention is to produce perforated telegraphic printer code tape from Morse code signals by mechanical and electronic means without the use of a human operator for reading the signals and perforating the tape.

Another obiect of the invention is to perform a code translation from Morse code to printer code by the use of electro-mechanical relays and simple electronic circuits, thereby avoiding intricate mechanical assemblages and errors due to the human equation.

Briefly stated, the present invention comprises apparatus which receives continental Morse code telegraphic signals, recties the Same, actuates various electronic trigger circuits from these rectied signals and, by a gating operation, sorts the Morse signals into dots, dashes, intra-letter Spaces. inter-letter spaces and inter-word spaces.

An advantage of the present invention is that there is no requirement that the incoming signal by synchronous, or in any way controlled from the receiving end. The translator apparatus of the invention accepts, without error, received signals varying in speed or weight, either one or a combination of both, to a total of i20% from a predetermined mean or average speed or Weight.

A more detailed description of the invention follows in coniunction With a drawing, wherein:

Fig. 1 illustrates the electronic translator circuit of the invention;

Figs. 2a, 2b and 2c, taken together, illustrate the relay counting chain for use with the circuit of Fig. 1;

3 is a series of curves which represent voltage and current variations at different points in the system of Fig. 1, given for the purpose of explanation; and

Fig. 4 is a series of curves given in explanation of the operation of the shift mechanism of the invention.

Referring to Fig. 1, there are shown various trigger circuits for sorting the dots, dashes, and spaces of the incoming Morse code signals and other trigger circuits for performing the printing function, the clearing function and the case shift function.

The incoming or received continental Morse code signal, which may be tone, is represented in line l of Fig. 3. This signal is represented by dots and dashes separated by spaces. The

dots cover the intervals between times A and B, and between G and l-i, While the dashes cover the intervals between C and F and K and N. The dot is shown as having a duration of one baud While the dash is shown as having a duration of three bands. The spaces appearing in the intervals B-C and F-G are each of one baud duration and are intewelernent spaces. The space covering the interval Irl-K is three bauds, in length and represents an intercharacter space, While the space covering the time interval N-S extends over a duration of nve bauds and represents a Word space.

The tone signal of line i rectied by suitable apparatus (not shown) to produce direct current pulses of mark and space, as shown in line 2 of Fig. 3. The marit of line 2 is of negative polarity While the space is of positive polarity. Thus the direct current pulses of line 2 are applied to the incoming line INC which connects With the grid of the amplifier and inverter vacuum tube Ib The output of tube iti, appearing at its anode, comprises pulses of the same wave form as the input but ci reversed polarity. This output is applied to the grid of the ampliiier-inverter vacuum tube ii and is shown in line 3 of Fig. 3. The output ci tube It is also applied to leads I2 and i3 through differentiator circuits RIS, CIE and RM, CIS, respectively, and also to lead Ill through difierentiator circuit RIT, CII'. The same output signal from amplifier inverter tube lil is also applied to leads Il and 22. The output of amplifier-inverter tube Ii which has the same polarity and wave shape as the pulses shown in line 2 of Fig. 3 applied to lead I5 through differentiai'or circuit RIS, CIB.

In order to sort the dots and dashes, there is provided a self-restoring marking trigger circuit lili? composed or" vacuum tubes V and VI Whose grids and anodes are interconnected regenera tively. This trigger circuit has one degree of electrical stability; namely, a stable state in which tube V is normally conducting and tube VI nonconducting, and an active state in which tube V is non-conducting and tube VI conducting. The time duration in Which the trigger circuit IBD remains in its active state is determined to a large extent by the time constants of the condenser C and variable resistor E, in series with a second resistor connected between ground and the grid of tube V. The anode of tube V is connected to the grid of tube VI through a condenser-shunt-resistor combination Ci, R2. The grid of tube Vi is connected through a resistor RI to the negative terminal of a source of unidirectional potential, 110 volts. In circuit with the cathode of tube VI is a diode D. Thetime constants of the trigger circuit Iii@ have such values that it will remain in the active state when triggered or red :for a time duration of one and one-haii bauds. In order to rire or activate the trigger circuit its, there is required upon lead I5 a negative impulse which is applied to the cathode of tube V I. It will be evident that the application of a negative impulse to the cathode of tube VI is equivalent to the application of a positive impulse to the grid of tube V I.

In circuit with the anode of tube VI is a triode vacuum tube 5b Whose grid is connected to the anode of VI and whose cathode is connected to ground through a diode DI shunted by a condenser. Tube 59 is normally conducting; that is, it passes current during the time the trigger circuit IOD is in its stable state.

' In circuit with the anode of tube V is a vacuum tube triode 5I Whose grid is connected t0 the anode of V and Whose cathode is connected to ground through a diode D2 shunted by a condenser. Tube Si is normally non-conducting during the stable state of the trigger IGI).

The current passing conditions of tubes 50 and 5i reverse themselves When the trigger circuit Ii is activated. Stated in other Words, when tube VI becomes conducting, a negative pulse from the anode of this tube will be applied to the grid of tube 59 and render tube 5t non-conductive. Similarly, when tube V becomes non-conducting` a positive pulse from the anode of this tube will be applied to the grid of tube 5I and render tube 5I conducting.

In circuit with the cathode of tube 5S and also in circuit with lead I2 is a self-restoring dot trigger iii i4 comprising vacuum tubes V2 and V3. Tube V2 is normally conducting and tube V3 normally non-conducting during the stable state of the trigger I! and the current passing conditions of tubes V2 and V3 are reversed during the active period of the trigger. The time duration of the active period of dot trigger IIJI is determined in a large measure by the time constants of condencer C2 and resistor R. This active period is just suicient to actuate a dot relay |533 in circuit with a dot dual triode vacuum tube |63', the latter having its grid connected to the anode of tube V2.

In circuit with the cathode of tube 5I is a selfrestoring dash trigger |02 comprising tubes V4 and Vi. Tube V5 is normally conducting and tube V! normally non-conducting in the stable state of this trigger and the current passing conditions of these two tubes are reversed in the active state. The operation of this dash trigger similar to the operation of the dot trigger` IBI, and the active time of' the dash trigger I02 is just suicient to operate the ldash relay |04 in circuit with dash vacuum tube` triode |84. whose grid is connected to the anode of tube V5.

The manner in which the marking trigger circuit Iii operates to cause either. the dot trigger IEI or the dashV trigger i532 to operate Will now be given with particular reference to the curves of Fig. 3: The impulses appearing on lead I5 in circuit with the cathode` of tube VI of trigger circuit iii are shown in line ofFig. 3. These im.- pulses are of relative positive and negative po.- larity and result from the differentiation of the square Wave pulses, in theoutput of. tube I I, shown in line 2. Since it requires a negative impulse to activate or trip trigger circuit IiIiLit Willbe seen from an inspection of line 5 (Fig. 3) that such a negative impulse appears at the start of a mark at time A. This negative, impulse will activate trigger IEE! which willfchange from its stable to its active condition and remain in the active condition for a periodof one and one-half bauds. Any positive impulse appearing on lead I5` will be absorbed by the diode D and has no eiect on the trigger circuit Iil. The anode voltage wave forms of tubes V and VI of trigger circuit Iii are shown i in lines and 'I of Fig. 3. Thus, referring to line of Fig. 3. it will be seen that the trigger circuit IDI) is activated at time A. and remains activated for one and one-half bauds until a time between B and C, at which time the trigger circuit will be restored to normal. At times C, G and K, corresponding to a position at whichnegative impulses appearA in, lead I5, line 5A of Fig. 3, the trigger circuit I will again be activated.

During the time trigger circuit I DI); is` in the active state, tube 50 will be non-conducting.' If,

pulse appearing on lead I2 will cause tube DI to conduct and dissipate the pulse. It will thus be seen that the dot trigger is red solely when the end of mark occurs during the active period of marking trigger |00. The anode voltage of tube V2 of dot trigger |0I and the corresponding current variations through dot relay |03 are shown in lines and 0, respectively, Fig.3. The dot trigger IOI cannot be fired or activated when tube 50 is conducting, due to the unfavorable division of input tripping pulse voltage between diode DI and resistor RI5.

The .negative impulses necessary to operate the 'dash trigger |02 and hence the dash relay |04 appear in lead I3 and are shown in line 4 of Fig. 3. However, these negative impulses in lead I3 cannot activate the dash trigger |02 during the time tube I is conducting, and since tube 5| is conducting for the entire active time of trigger |00, it will be seen that the dash trigger |02 can operate only after the restoration of the trigger |00 to normal. Since trigger circuit |00 has an active period of one and one-half bauds, which is a time interval longer than a dot, it will be clear that the dash trigger |02 can only operate when an incoming dash signal element is received. Thus, referring to line 4, the rst negative impulse which operates the dash trigger |02 occurs at the end of the rst dash at time F, at which time trigger circuit |00 is in its stable, state. The next negative impulse for operating the dash trigger |02 occurs at the end of the second dash element at time N, at which time trigger |00 is again in its stable state. The anode voltage curve for the dash trigger |02 and the corresponding current variationsk through the dash relay |04, are shown in lines I0 and II, respectively. To summarize, the dot trigger IOI and the dot relay |03 are operated at the end of every dot, while the dash trigger |02 and the dash relay |04 are operated at the end of every dash element. Actually, the dot trigger IOI will operate at the end of the dot regardless of ywhether this dot is less than a baud or greater than a baud, provided it is less than one-half bauds; while the dash trigger |02 will operate when the mark element or dash is longer than one and one-half bauds.

The trigger circuit |05 is known as the spacing trigger circuit and is of the self-restoring type similar in operation to the trigger circuit |00. It comprises two vacuum tubes V6 and V'I, tube V6 being normally conducting and tube VI normally non-conducting in the stable state, and vice versa in the active state. The active period for the trigger circuit |05 is one and one-half bauds. This trigger circuit is fired from negative impulses appearing in lead I4, shown in line 4 of Fig. 3. These negative impulses for ring or activating trigger circuit |05 appear at the end of every mark. The anode voltage wave form of tube V6 of the spacing trigger circuit |05 is shown in line I2 of Fig. 3.

The voltage wave form for the anode of tube V1 is not shown in Fig. 3 but is the inverse of that shown inline I2. It will be noted from an inspectrigger circuit |05 lires, it appliesra positive pulse to the grid of a normally non-conducting tube 52 and causes tube 52 to conduct for the duration of the active period of the trigger circuit. When tube 52 conducts, there will be applied a positive pulse from the cathode of tube 52 via lead 20 to the anode of diode D5 in circuit with the print trigger circuit |01. It should be noted at this time that the cathode of the amplier-inverter tube I is also connected directly to lead 20 and hence to the anode of diode D5. During marking periods, the pulses applied from the cathode of amplier-inverter I| to lead 20 are of positive polarity. Thus it -will be seen that during marking intervals and also during the time when the spacing trigger circuit 05 is activated there is always a positive pulse on lead 20 to cause diode D5 to conduct. When diode D5 conducts, it prevents the activation of the printing trigger |01 from impulses on lead I8, as will appear hereinafter. y

To properly sort out the spaces of the incoming Morse code signals, there is provided another selfrestoring trigger circuit |05 which is similar in operation and arrangement to the spacing trigger circuit |05 and the marking trigger circuit |00 except for the fact that the active period of the trigger circuit |06 is two and one-half bauds. This trigger circuit comprises vacuum tubes V8 and V9, the former being normally conductive and the latter normally non-conductive in the stable state, and vice versa in the active state. In circuit With the cathode oi tube V9 there is provided a diode D4 and also a vacuum tube 50 whose cathode is connected through lead I6 and differentiator circuit RIS, CIS to the anode of tube V5 of the spacing trigger circuit |05. The grid of tube 60 is connected to lead I'I which extends to the anode of the amplier-inverter tube I0. The signal which appears on lead II and thegrid of tube 60 is shown in line 3 of Fig. 3. Tube 00 is conducting on the marking signals and non-conducting on the spacing signals. Thus, tube 60 is conducting between A and B, between C and F, between G and I-I, and between K and N. During the time tube is conducting, there is a positive potential on the anode of diode D4 which causes this rdiode to conduct and hence prevent the activation of trigger circuit |06 through lead I6. It will thus be seen that the only time trigger circuit |05 can operate is during the spacing intervals when tube is non-conducting. Trigger circuit |06 is activated from its stable to its active state solely upon the restoration of spacing trigger |05 toits stable state. Since lead IB is connected to the anode of tube V6 of trigger circuit |05, it will be seen that when the spacing trigger circuit |05 restores itself to normal after one and one-half bauds in the active state, there will be a negative pulse on the anode of tube V5 which, when differentiated by RI 9, CI 0, will cause a negative impulse to appear on lead. I3 to re or activate trigger circuit |06. The impulses resulting from the differentiation of the negative pulse .on the anode of tube V6 of trigger circuit |05 are shown in line I3 of Fig. 3. Y The function of the spacing trigger circuit |05 is solely to delay the operation of the two and one-half baud trigger circuit |06. Since the trigger circuit |00 can operate only at the restoration of the trigger circuit |05 and in the absence of a mark, it will be seen that the trigger circuit |05 operates one and one-half bauds after the end of a mark, or one and one-half bauds after the beginning of ya space, because the trigger circuit commences its active period at the end ofv a. mark or atthe beginning of a space.

The anode voltage wave forms for the tubes V8 and V9 of the trigger circuit |06 are shown in lines I4 and I5 of Fig. 3. It will be seen that the first negative impulse on lead I6 (line I3, Fig. 3) 4capable of operating trigger circuit |06 occurs at a time between I and J, inasmuch as-this time is during a spacing interval and at the end of the active period of the trigger circuit |05. (Note line I2, Fig. 3.) The next time trigger circuit |59 is red is at a time between O and P, as will be seen from an inspection of line I4, Fig. 3.

The anodes V3 and VS ot the trigger circuit |06 are connected through difierentiator circuits R29, C29 and R2I,.C2I to leads I9 and I9 respectively. The negative impulses appearing on leadv I9 resulting from the differentiation of the output pulses from tube V9 on the activation of trigger circuit |55 are utilized to activate the self-restoring print trigger circuit It? at these times. The negative impulses appearing on lead I8 resulting from the differentiation of the output pulses from tube V9 on the restoration of trigger circuit |65 are utilized to activate the trigger circuit |01 whenever a marking signal has not occurred during the active time of trigger circuit |96. The print trigger |01 is similar in operation to the self-restoring trigger circuits Iii-I and |32. Print trigger tubes, 63, 5| and 52. Tube 52 is normally conducting and tubes 53 and 5I normally non-conducting in the stable state and vice versa in the active state. In the cathode circuit of vacuum tube 63 is a diode D5. In circuit with the cathode of tube 6I is the diode D5, which, when conducting., prevents the print trigger circuit |01 from becomingv activated by negative impulses on lead I8. The impulses which appear in leads I8` and I9 are shown in lines I5 and I1 of Fig. 3. The current' variationsl through diode D5 are shown inline I8 of Fig. 3. lThe anodevoltage waveform ortube 62 of' the print trigger It? is shown in line Iej of Fig. 3; At therisk of repetition, it should be observedV that the print trigger circuit |01 cannotv operate withA a negative impulse on'lead I8 resulting fromA the restoration of trigger circuit to itsy stable state if a mark has occurred during the active period of trigger circuit |06. This results from the locking action of tubesV |I and 52 in causing D5 to conduct andpreventing the print trigger circuit i5? rcmoperating. Dur-- ing the mark, tube I I is conducting, and applies a positive potential through lead 2G to cause diode D5 to conduct. An inspection of curves I5, I1, Iii and I9 ci Fig. 3 will show that theprinttrigger circuit M1' becomes active solely during theA time thereis no current through the diode D5, andthis activation of the printing trigger occurs under this condition upon the application of a negative impulse on leads I8 or I9.

In circuit with the output of the" print. trigger |01, there is provided a pair of normally cut-oir printing pentode tubes 54 and 55. The anodes of these two pentode tubes are connected through a permutation of selecting switches S to any of a plurality of` solenoids 56. In practice, there are. thirty-two such solenoids 56, one for each character, key on the printer perforator and approximately nity selecting switches S under the control of counting relays. There is a permutation of selecting switches for each Continental Morse character to be selected.

When the print trigger |01 becomes activated, the tube 52 willI become non-conducting and |01, however, comprises three vacuum will` pass a positive pulse through its anode to the grids of pentodes 54 andy '55,` thus kcausing these two tubes to pass current for the duration of the active period of the print trigger circuit |01, and hence cause theactuation of the proper printing solenoid 56. The activeV time ofV print trigger |01 is just sufiicient to operate solenoid 56,.

In circuit with the cathodes` of the pentodes 54 and 55 is a self-restoring clear trigger circuit IIi9` comprising vatuurn tubes VI 2 and VIB. Clear trigger circuit |09l operates in the same manner as trigger circuits |0I and |02. When conduction ceases in tubes 54-and 55, the cathodes of these two tubes assume a negative potential, volts, and apply a negative pulse through. lead 23 to the grid of tube VI3, firing the trigger circuit I09. In the stable stateof trigger circuit m9, tube VII:` is normally conducting and tube VI2 normallyl non-conducting and the current passing conditions of these two tubes are reversed in the active state. In circuit with the anode 0f tube VI3 is the grid of a triode vacuum. tube 98 whose anode is connected to the winding of. clear relay |i1. Tube 98 is normally non-conducting and is caused to conduct when trigger circuit |09 is activated. The function of the clear relay I`I1 is tore-set all of the reays: of the counting chain to be described later. The clear trigger circuit |69 is activated whenr the tubes 54 and 55. are cut-ori due to the restoration of the print trigger circuit |01;

The current variations through the printing solenoid 59 are represented by the Wave form. of line 20 oi Fig. 3. The anode voltage of" tube V:I3 on clear trigger circuit |09 and the current variations in the winding of clear relay |I1 are shown in line 2| of Fig. 3. It will be noted that the clear trigger circuit and the clear relay operate only at the termination ofthe operation of the printing solenoid and that this clear trigger cir;- cuit and clear relay are'restored to their normal conditions prior to the application of another printing pulse.

In summarizing the sorting or gating operation ofthe system of the invention, it will be noted that the dot trigger I9| is. operated when there occurs a mark element ofV one baud duration- `(or less than one and one-half bauds) and that the dash trigger circuit |02 is operated when there occurs a mark of three bauds duration (or more than one and one-half bauds). Similarly, the trigger circuit I05isoperated but nothing else when there occurs a space element of4 one baud duration (or less than one and one-half bauds). If there occurs a spacel of three bauds duration (or more than one andk one-half bauds), then the restoration of the trigger circuit |05 will operate trigger circuit |06; whose operation in turn will activate trigger circuit |01 and cause a single printing operation over a selected solenoid 56. circuit cannot operate until the restoration of'trigger circuit |05, and trigger circuit |05 is activated for one and onehalf bauds duration, then it will be obvious that trigger circuit |06 does not start until one and one-halt bauds of space elapse. Inasmuch as active time oi trigger circuit |551 is twov and one-half4 bauds duration. It will be evident that it does not restore itself until oneiand'one-hali plus-two and one-half` (or four) bauds after thestart of ay space. When trigger circuit |06 restores itself, it will operate print trigger circuit |01 via lead I8; provided no marking signal has intervenedto--lock the print trigger circuit loi-'mits stabieiposiuon.

Actually, the print trigger circuit |01 is operated immediately after one and one-half bauds of space, when trigger circuit |06 is activated, and this occurs via the impulse on lead I9. The print trigger circuit |01 again operates after four bauds of space, under the conditions set forth above. The system thus functions promptly to identify inter-character and word spaces at a predetermined time before the spaces are completed, hence enabling the re-setting of the print solenoids and relay chains in ample time for the acceptance of a new Morse code combination.

Similarly, the dot trigger circuit functions immediately after the receipt of a dot, even though this dot may have a weight more or less than one baud, provided the weight is less than one and one-half bauds. Also, the dash trigger circuit functions immediately after the end of a mark, so long as this mark exceeds one and one-half bauds no mattel` what the duration of this mark may be. It will thus be evident that the system provides a high degree of tolerance in Weight (percentage mark-to-space) and speed of signal elements constituting each code combination.

An advance relay 99 is provided which operates via lead 22 and triode 51, and repeats the marking signal. The winding of advance relay E19-is in circuit with triode 51 whose grid is connected to ground through resistor R30 and to the anode of diode D1. During markingLwhich causes the application of a positive pulse to lead 22, the diode D1 Will be non-conductive, at which time the grid of tube 51 Will be at ground potential through resistor R30, causing tube 51 to conduct and energize the Winding of advance relay 99. In the absence of a marking signal on lead 22, diode D1 will be conducting because the anode of this diode Will be positive relative to its cathode, as a result of which `the IR drop through resistor R30 is of sufticient magnitude to bias the tube 51 to cut-off and interrupt the flow of current through advance relay 90. It should be noted that the anode of tube 51 obtains its positive polarizing potential through the Winding of advance relay 99 and through selector switches S and the Winding of the selected print solenoid 56. During the printing operation, the drop in voltage through the printing solenoid is of such av magnitude as to prevent the energization of the advance relay 99. This interlocking action prevents the setting up of a false character in the relay chain during the printing operation. The current variations through the advance relay 90 are shown in line 22 of Fig. 3. An inspection of line 22 and line 3 of Fig. 3 will show them to have substantially similar wave forms.

Fig. 2 shows the chain of relays for causing the operation of the various printing solenoids 56, and also shows other relays together with an electronic circuit for changing from lower case (letters) to upper case (figures). There are six dot relays DORI to DORE inclusive and six dash relays DAR! to DARS inclusive. These relays constitute a counting chain. Relay DOR! and dash relay DAR! form one pair of relays in the counting chain, and relay DOR2 and relay DAR2 form another pair in the counting chain etcetera, While relay DORS and relay DARE form the last pair in the counting chain. There is also provided another chain of relays, relay AR! through relay ARE, called the advance relay chain. These last relays are operated from the advance relay 9S. The advance relay chain is, in eifect, a stepping relay causingthe dot or dash signals to be switched from one pair of relays `in the dot n contact 2 I3 and holding bus 235.

:ing signal, whether a dot or a dash, in any letter ,received in any code combination, cannot operate ,relay AR! because of the fact that the contacts and dash chain to another pair or relays inthe chain. The relays DORi through DDR5 are oper-f ated from the contacts of the dot relay |03, Whilev the relays DAR! through DARS are operated from the contacts of the dash relay |86.

n order to simplify the drawing, certain con--A tacts on the relays, DOR! through DORS, and DAR! through DARG, have been illustrated on Fig. 2c, and these perform the permutations which select the proper printer solenoids 55. The various contacts on the relays DAR! through DAR and DOR! through DORS which perform the permutations for operating the selected solenoids are represented by the reference character S.

A description of the operation of the chain relay system of Fig. 2 will now be given: From what has gone before, it will be understood that the dot relay |03 operates every time a dot marking signal has been identied, While dash relay |54 operates every time a dash marking signal has been identied, and advance reay @il operates every time a marking signal occurs. Dot relay |03 and dash relay |04 operates at the end of every dot or dash respectively, While advance relay 9s operates during the marking signal whether a dot or a dash. Solenoid 55 operates after 11/2 bauds of space or after the spacing signal hasy been identified as either an interletter space or word space.

The operation of dot relay |03 closes its con tacts and causes the application of a positive potential to lead 200, and this positive potential follows a path through break contacts 20| of relay DARI, lead 2%2 and break contacts 203 to the Winding of relay DORl, thus energizing relay DOR! and causing this relay to lock up over its make contact 20d and open the break contacts 203. The contact Zilli, for locking relay DOR! in its operativelposition, connected through a resistor 205 to bus 206 which, in turn, is connected to a source of positive potential through the break contacts of the clear relay ||'|.v lt should be noted that this common lead or bus 206 furnishes the locking or holding potential for all the relays DOR| through DDR6, DARI through DAR, and ARI through ARB.

The operation of relay DORI opens the break contacts Zl which form a path for operating relay DAR! in the event dash relay |04 should operate. v

The operation of relay DOR! also closes a path over a pair of make contacts 259 to enable the operation of relay ARi over a circuit extending from the make contacts of advance relay 99, lead 2li), through the make contacts 209, lead 2||, break contacts 2 |2 of relay AR! and the winding of this relay. Since the advance relay 00 operates during every marking signal, it Will thus be evident that the occurrence of the second marking signal, whether a dot or a dash, Will operate relay ARl and cause AR! to lock up over its make The iirst mark,-

on relays DORE and DAR! for operating relay contacts 2I1 of relay DDR2, lead 2I8, break contacts 2I9 of relay DARZ to the winding of this relay. Whenrelay DARZ operates it will lockv up over its make contact 22B and holding bus 285.

The closure of DARZ prepares a path for the operation of relay ARZ upon the operation of advance relay 99 on the third marking signal and opens the circuit from lead 20u on which a pulse might otherwise operate relay DDR2.

The occurrence of the third marking signal will cause the advance relay 99 to operate relay ARZ over a path extending from the make contacts of the advance relayBS, lead ZIB, make contacts 2Q!) of operated relay DORI, lead 2Il, make contacts 22| of operated relay DAR2, lead 222 to the break contacts 223 of relay ARZ, and to the winding of this relay. The operation of relay AR2 causes it to lock up over its make contact 224, and prepares a path for the operation of relay DDR3 or DAR3 depending upon whether or not this third marking signal is a dot or a dash. If this third marking signal is a dot as shown ih line I of Fig. 3, then the operation of dot relay ID3 at the end of this mark will cause the operation of re"ay BORR over a path extending from lead 20th/'make contacts 225 of operated relay AR2, lead 226, break contacts 221 of relay BARS', lead 228, to the break contacts 229 and the winding of relay DORS. Relay DORZ, upon being energized, locks up over its make contact 230.

The next marking signal will operate advance relay 99 and cause the operation of relay ARS provided, prior to this time, the space is not suflciently long enough to cause the printing operation.` If the signal of line I of Fig. 3 is being received, a printing operation will occur before the receipt of another' marking signal, due to the fact that the space between times H and K is three bauds long.` Since the first three marking elements of line I of Fig. 3 represent the letter R, a study of Fig. 2c of the permutation switching contacts S will show that switching contacts for relay DORI, DARZ and DORS will be operated to the left (which is the energized position) and prepare a path for the operation of the printing solenoid 58, represented by the letter R. The path for printing solenoid R is traceable from the plus 1,20v volts lead 3M, through the printing Solenoid R (and the numeral 4), lead 39|, unoperated or right contacts 352 of relay DAR/I, un operated contact 3%3 of relay DDR4, lead 334, operated or left contact 3ll5 of relay DORS, lead 356, operated contact 301 of relay DARE, unoperated contact 308 of relay DOR2, lead 3D3, operated contact SIG of relay DORI, and lead 3l I to the anodes of printing pentode vacuum tubes 54 and 55.

Assuming that a fourth marking signal had followed the r'st three marking signals and after a :spacing interval of only one baud, then there would not have been a printing operation, and lthe advance relay 99 would have caused the operation of advance relay AR3 which would have prepared a path for the operation of relay DOR@ or DARA depending upon Whether or not the fourth marking pulse was a dot or a dash. Similarly, it will be obvious that additional marking signals will operate relays ARA and ARE preparing the 'pathsfo/r the operation of relays DORS and DARE, DORFJ` and DARE respectively, depending upon whether these fifth and sixth marking ele- -inents are dots or dashes.

The opration of the Case Shift feature of the invention will now be described: Many of the solencids 56, it will be observed, have both a letter and a numeral shown. On the printer perforator these numerals appear on the same key as the corresponding letters, that is, as the upper case character of the letter. Thus a Morse code combination for the numeral 4 must operate the same perforator key, and therefore the same solenoid as the letter R. However, the operation of the solenoid for the numeral must be preceded by the figure shift combination. In order to assure that the following character will be registered in lower' case, should it be a letter and not a numeral, a letter shift combination must follow' the printing of every numeral. The letter code combinations include at most only four marking signas, while the numeral (upper case) code combinations include at least five marking elements and sometimes six marking elements. When more than four marking elements are received, the figure solenoid (upper case) 12 will. operate due to the operation of shift relay 15 and the shift trigger H38. This occurs as follows: The receipt of a fifth marking element causes the advance relay 99 to operate relay ARll. ARA operates to lock up in the manner described for relays ARI, ARZ and ARS. The operation of relay ARA prepares a path for the operation of relays DORE and DARS depending upon whether this fth marking element is a dot or a dash. In addition relay ARA, in operating, operates the shift relay 15 over a path including a source of positive potential on lead 23|, the make contacts 2.22 of relay AR4, lead 233, and break contacts 234 and winding of the shift relay 15. When the shift relay 'l5 operates, it locks up over its make contact 235 and the break contacts of shift release relay 76.

When shift relay 15 is unoperated or in its normal position, it should be noted that a path is closed to the letter solenoid 13 over a path including lead 3Q!) on which there appears a voltage of volts, the winding of letter solenoid 13, lead 3| 2, lower break contact 3| 3 and armature SI of shift relay 15, and lead 3I4 extending to the anodes of pentode vacuum tubes 10 and 1I. Pentodes 1I) and 1I only operate in response to the operation of shift relay 15 as will appear hereinafter. Thus, while letter code combinations only are being received, the letter solenoid 13 and the shift relay 15 will be unenergized and the circuit will be on the letter shift or lower case position. When numeral or gure signals are being received, which is characterized by more than four marking signals, the operation of relay AR4 by the fth marking signal will cause the operation of relay 15 which locks up. The operation of shift relay 'I5 will cause armature Sl to disengage break contact 3I3 and cause armature SI to engage make contact 3I5, thus closing alpath through the figure solenoid 12 over lead 3 6.

It should be noted that lead 14 which extends to the trigger circuit |08 is connected through break contact 3II and its associated' armature S2 to the negative terminal of a battery of 120 volts. Thus when relay 15 operates, the armature S2 disengages break contact 3I1 and travels toward and engages make contact 3 I8. During the travel `time of the armature S2 from the break contact 3I1 'to the make contact 3I8 a pulse of relatively positive voltage is vimpressed on lead 14 due to the momentary removal of the minus 120 volts. This pulse has no effect on the trigger circuit. When, however, the armature S2 of the shift release relay 'I5 engages the make -contact 3ll8.

vthe trigger circuit |08. The shift trigger circuit |08 is similar in operation to the print trigger circuit |01 of Fig. l and comprises vacuum tubes VIO and VI I. Tube VID is normally non-conducting and VI I is conducting in the stable state of the trigger circuit, and the current passing conditions of these two tubes are reversed in the active state. When the shift trigger circuit |08 is activated, tube VII will cease conducting and pass a positive pulse to the grids of pentode tubes 10 and 1I, thus causing these two pentode tubes to pass current and complete the path to operate the gure solenoid 12. The shift trigger circuit |08 has a time constant which causes it to remain in the active state for a time interval sufcient to operate solenoids 12 or 13.

At the end of the Morse code combination constituting the particular figure r numeral being received, print trigger circuit |01 will operate and cause the operation of the desired printing solenoid 56. After the termination of operation of the selected printing solenoid 56, the clear relay II1 will operate through the clear trigger circuit |09, as a result of which the break contacts on the clear relay II1 will open and the positive potential on the holding or locking bus 206 for the chain relays will be removed, causing all of the chain relays to become de-energized and restored to normal. When relay ARA is restored, a path is completed from the winding of the shift release relayr through lead 236 and through the break contacts 231 of relay AR4, lead 238, to the lead 2I0 and the make contact of advance relay 99. When the rst marking signal is received for the succeeding letter or gure, the advance relay 99 will operate and apply a positive potential to operate the shift release relay 16 momentarily over the path just described. The operation of the shift release relay 15 will remove from its break contact the positive holding or locking potential for the shift relay 15, thus causing shift relay to become cle-energized, as a result of which armature SI of shift release relay 15 will again engage break contact 3|3 and close a path to the letter solenoid V13, simultaneously breaking the circuit to the gure solenoid 12. The restoration of shift relav 15 to normal will also cause armature S2 of this relay to disengage make contactl and to engage contact 3| 1. When the minus 120 volts is re-applied to make contact 3I1, there is a negative pulse applied to lead I4 extending to the shift trigger circuit |08. This negative pulse on lead 14 is differentiated by condenser C22 and resistor R22 and fires or activates shift trigger |08 to cause pentodes 10 and 1I to pass current, as a result of which a circuit is completed through the space path of these pentode tubes, switch SI and make contact 3I3, and lead SI2 to operate the letter solenoid 13, thus restoring the circuit to the letters or lower case position. The circuit is now ready to receive another code combination of Morse code signals.

The operation of the shift mechanism is graphically illustrated in Fig. 4 wherein line 23 indicates, by way of example, a Morse code combinationk for the numeral 5 followed by the letter E. I The pulses of positive polarity shown in line 23 are produced by the operation of the advance relay 99 which operates for every marking signal. It should be noted from line 24 of Fig. 4

vdots and dashes and spaces by electronic circuits, and utilizes the outputs of these electronic circuits ing signal.

vof the trigger circuits.

14 that relay AR4 operates at the beginning of the fth marking signal and remains closed until the operation of the clear relay II1 as indicated in line 25. The clear relay II1 operates following the operation of the printing solenoid 56 as shown in line 29. Line 26 of Fig. 4 indicates that the shift relay 15 operates substantially simultaneously with and from the operation of relay ARA. The shift relay 15 releases upon the Vfirst operation thereafter of the shift release vrepresents the current in the ligure solenoid 12 and shows that the iigure solenoid 12 operates upon the operation of the shift relay 15. The wave form of line 29 represents the current in the printing solenoid 56 for the particular figure or letter selected, and this printing solenoid operates after the operation of the figure solenoid 12; that is, after one and one half bauds of spac- The wave form of lline 30 represents the operation of the letter solenoid 13. It should be noted that the letter solenoid 13 operates upon the release of shift relay 15 which corresponds in time position with the start of the next marking signal following the numeral code combination. The operation of the gure solenoid 12, the printing solenoid 56 and the letter solenoid 13 must follow one another, as shown in lines 28, 29 and 30, and no two of these solenoids should overlap at any time in operation.' Line 29 shows that the second operation of the printing solenoid 55 for the letter E follows the operation of Ythe letter solenoid 13.

It should be understood that the invention is not limitedV to the particular polarities of the potentials shown for operating and locking the relay chains and operating the trigger circuits, since, it will be obvious that by suitable design of the circuit, other potentials may be used to operate and lock up the relavs and other potentials can be used to operate the trigger circuits by applying suitable impulses to selected tubes Since the advance'relay 99 and the relays ARI through ARE function as 'stepping relays, it will be appreciated that these relays can be replaced by a single stepping relay having a plurality or" `wiping contacts.

Since the sclenoids 55 are mechanical means for actuating the key levers of a perforator or a typewriter or other suitable transcribing devices, it will be evident that the final utilization circuit 'operated by the solenoids 59 may be either a 'live-unit. siii-unit, seven-unit or other multi- 'unit printing tape perforating machine.

In summation. the system o f the invention receives continental Morse code signals. sorts out for operating a relay chain which controlsthe selection of solenoids for transcribing the received Morse code signals into another code.

What is claimed is: l. A circuit arrangement for discriminating between code elements of different time durations storing electron discharge device trigger circuit coupled to and under control of said rst trigger circuit andl operatively responsive to the trailing edge `of a mark element Whose duration is less than the .active time of ysaid 'first trigger circuit, and a third self-restoring electron discharge den vice trigger circuit under control of ysaid ilrst trigger circuit and operatively responsive to the trailing edge of a mark ele-ment Whose duration is longer than the active time of said ilrst trigger circuit.

2. A circuit arrangement for discriminating between dots, dashes and spaces Yof predetermined code signals, said :dots and dashes comprising mark elements ,of ldiierent time durations, in-

cluding a marking electron discharge deviceI trigger circuit Voperatively responsive to the start .of every mark element and having .an active time longer than the dura-tion ci a dot, a dot electron discharge device trigger circuit coupled to and under control 4of said marking trigger circuit :and operatively responsive to the end of a mark element whose duration is less than the active time of said marking trigger circuit, and .a dash electron discharge device trigger circuit coupled to and under control of said marking trigger circuit and .operatively responsive to the end of a mark element Whose duration is longer than the active time of said marking trigger circuit.

3. A circuit arrangement for discriminating between dots, dashes and spaces of predetermined code signals, said dots and clashes comprising mark elements of different time durations, in cluding an input circuit to which said signals are applied .and coupled thereto a marking electron discharge device trigger circuit operatively responsive to the istart -of every mark element, and having an active time longer than the duration of a dot, a dot electron .discharge device trigger circuit coupled to and under control of said marking trigger circuit and operatively re sponsive to the end of a mark element whose duration is less than the active time of said marking trigger circuit, a electron discharge device trigger circuit coupled to and under con trol of said marking trigger circuit and operatively responsive to the end of a mark element whose duration is longer than the active time of said marking trigger circuit, an output circuit coupled to said dot trigger to deliver signals corresponding to said dots and another output .circuit coupled to said dash trigger to deliver' signals corresponding to said dashes.

4. Apparatus for converting Morse code sign nals utilizing dots, dashes and spaces for the code combinations to other code signals, said dots and dashes comprising mark characters of different time durations, including a marking trigger circuit responsive to the start of every mark character, and having an active time longer than the duration of a dot, said marking trigger circuit including a pair of grid-controlled `electron discharge devices whose anodes and grids are inter-connected reg-eneratively, one device being normally conductive and the other device .normally non-conductive in the stable state and vice-versa in the active state of said trigger circuit, a pair of electric tubes each having an anode, a cathode and a grid, a connection from the anode of the normally non-conductive device of said trigger circuit to the grid of one electric tube, a connection from the anode of the normally conductive device of said trigger circuit to the grid of the other electric tube, a diode shunted by a condenser in the cathode circuit of each electric tube, whereby said electric tubes are alternately conductive. one being conductive in the vstable state of said trigger circuit and the other being conductive in the active state of .said trigger circuit, a dot trigger circuit connected to the cathode of that electric tube associated with said normally non-conductive device, a dash trigger circuit connected to the cathode of that electric tube associated with said normally conductive device, and means for supplying negative impulse to said dot and dash trigger circuits at the end -of every mark character.

5. A circuit arrangement for discriminating between elements differing in time duration of prearranged code signals, said code having mark elements and interposed yspace elments arranged in combination to correspond to individual characters of said code, inter-element spaces 'being of given duration, inter-character spaces being of another duration, and the word .space being still a different time duration, including .a circuit to which said ,code signals are applied, and coupled thereto a rst self-restoring trigger circuit having a stable and an active state and responsive to the .end .oi a mark `.elenfient, a second self-restoring trigger circuit coupled to and responsive to the restoration ci said first trigger circuit, said second trigger circuit having an active time duration which is longer than that of said rst trigger circuit, .a third selfrestoring trigger circuit having a pair of connections coupling the .same to said second trigger circuit and beingT responsive to both the activation and restoration of said second trigger circuit, and means to prevent the operation of both said second and third trigger circuits during the presence of a mark element.

6. Apparatus for identifying the character .of the space of a continental Morse code signal, comprising a first self-restoring trigger circuit having a stable state and an active state, the active time of said trigger circuit being substantially 11/2 bauds a circuit to which said Morse code signals are adapted to be supplied, means coupled to said circuit and operative in response to signals therein for tripping said trigger circuit from its stable to its active state at the beginning of a space, a second self-ref=toring trigger circuit coupled to and responsive to the restoration of ,said iirst trigger circuit` the active time .of said second trigger circuit being substantially 21/2 bauds, a third selfmrestoring trigger circuit coupled to and responsive to the tripping and restoration of said second trigger circuit, means to prevent the tripping of either said second or third trigger circuits during the presence of a mark signal, and an indicating circuit coupled to the output of said third trigger circuit.

7. In combination. a iirst self-restoring trigger circuit having a pair of output connections, second and third self-restoring trigger circuits, electronic means between one of said output connections and sait second trigger circuit for conditioning said second trigger circuit to operate, electronic means between said other output connection and said third trigger circuit for conditioning said third trigger circuit to operate, said two electronic means being alternatively conductive, a pulse input circuit for supplying to said rst trigger circuit a pulse of such polarity and magnitude as to trip said rst trigger circuit at the start of said last pulse, and indivi-,dual differentiator circuits coupling said second and third trigger circuits to said pulse input circuit for supplying to said last trigger circuits impulses at the end of said pulse of such polarity and magnitude as to trip only that second or third trigger 17 circuit which is conditioned to :operaterby i associated means. j

8. Apparatus for .converting Morse code signals having mark-and 'space characters for every code combination to other code-signals, including a rst self-restoring trigger circuit responsive `to the startof` every mark element, a second self-restoring trigger circuit under lcuntrol of said first triggercircuit and responsive to the trailingedgeof a mark'lelement whose duration is less than the active time of said first trigger Y circuit, and a third selferestoring trigger circuit under control of said first trigger circuit and responsive to the trailing edge of a mark element Whose duration is longer thanftheactive .time of said Irst trigger circuit, a fourth. Lself-restoring trigger circuit having a stable and an active state and which is responsive to the end ofamark element, a fifth self-restoring trigger circuit coupled to and responsive tothe restoration', of said fourth trigger circuit; vsaid fifthu trigger circuit having an active time duration which is longer than `that of -said= fourth trigger circuit, .and a sixth self-restoring-rtrigger Vcircuit `having a1 pair of: input ,connections extending toer-the outputs of said sixthtrigger circuit for lenabling ,the tripping of said iifthvtrigger circuit at-both the activation `and restorationof sai'dliifth-trigger circuit, and means topreventA the activation of 4both said fth and sixth trigger circuits during thepresenceof amark element. Pif.. .t 1

' 9; Apparatus ,for converting Morse ede-Isig,- nalsjv having mark and space elementsgfor every -code combination to othercodezsignals, including a first self-restoring trigger circuit-responsiveto the start of` 'every mark element, asecond self- -restoring triggercircuitaunder control of-vsaid rst triggercircuit and'responsive tothe trailing edge of a-mark element whose duration is less than the active time of said'rst trigger; circuit,

vand a thirdself-restoring trigger circuit under control of said 'first Ytrigger circuit and responsive to -the -trailingfedge ofa mark element whose duration is longer'thancthe active time-of said ger-"circuit having -a-stable and an activestate fand which is responsiveftothe-end of -Ya '-mark Yelement, Aa `-fifth self-restoring trigger circuit 'coupled toandresponsive rto the f-\restoration-of said Tfourth trigger circuit, YVsaid `1iifth-vtrigger .circuit having an ,active time duration-whichY iis longer than that-of-'said fourth-triggercircuit, and a =siXth self-restoring trigger circuit "having -apairof 'inputconnections extending -toV the outputs of said fifth trigger-circuit-forenablingmthe -rtripping of said sixthftrigger circuit at both\-the activation and restorationf-ofesaid-'iifth trigger circuit; andmeans to prevent-the activation `or" ,fboth said fiifth and sixth-triggercircuits during thepresence of a mark- -element, a relay chain Vunder` control-of -said Isecorrdfand;third? trigger circuits, -a plurality` offsolenoids[WhoseV operating paths are controlledby the setting offsaid relay chain, andw-means `,for operating the-selected solenoid Vunder\-j,control 'of said sixth trigger circuit.; fr f L" X '10. lApparatus,-or converting -Mo rse code sig- 'nals ,Y yutilizing dots,- v:dashes and'spaces lfor -the code combinationstoother'cOde signalssaid dots and'dashes comprising mark elements ofs different duration f, a fdotraizdct trigger circuit under control of said marking triggencircuit -and-responsive 60 erating`,. paths arev under control V of y.the contacts .of lsaid relayameansincluding electronic,-`A

to the -end of a, mark element whose duration is less than the active time of said marking trigger circuit,-a dash triggercircuit under control of said marking trigger circuit and responsive to 5' the end of a mark element whosefduration'is longer than the active time of said marking trigger circuit, a chain of relays under control of A said-dot and dash trigger circuits, and a stepping relay operativedat-the-start of each dotand dash for advancing the operation of the relaysinA said Y ll, Electronic apparatus for sorting spaced dot and dashmark elements of a code signal, comprising an inputcircuit upon'which is impressed dot and dash D. C. signals, a rst ampliiier and Y-tionssecond and thirdA self-restoring .trigger cir,-

cuits, means-betvveen one-of said output connections and saidsecond trigger` circuit for conditioningsaid second trigger circuit to operate, `Ineans between said otherl output connection and saidljthird trigger circuit .for conditioning said ,third trigger circuit tooperate, said last .two meansf `beingalternatively conductive, a .connection including a .differentiator circuit from the output .of said second :tube tdthe input ofsaid first trigger. circuitgfor tripping the same at the startni-a--inarkl element, and individual. diierentiator4 circuits-.couplingthe .ou-tputoi: said rst tubelrtosaid` second and thirdtrigger circuits `for tripping` onlyfthat second or third .trigger circuit kwhich is conditioned-to operate by its associated e f1.2,lMorse code., signal v,converting Y apparatus vcomprising awchain-of dotand dash electromagneticLxrelaysr, a pluralityn of ,-.solenoids whose operating pathsare.undercontrol` of the contacts ilot saidy relays, .means including electronic discharge device circuits for operating a dot; relay in saidchain when aF dot signal is received, means including electronicv discharge circuits for operatinga ,dashrelay` in-fsaid -chain when a--dash signal4A is received,means responsive to thefoperatiorigojff .saidfldot and .dash-y relays; `for advancffing the operation. for -the relays in Y said chain, electronic discharge device circuits `for separating spaces of different durations to thereby-distingguish.. between inter-element spaces` and intercharacter and -inter-Wordgspaces, andl connections for operating a, selected solenoidvbvsaid last electronicdischarge device circuits at the end of .every character` signal .code combinationg-anld word signal codeicombination. Y f v 13. Morse.L .code signal converting apparatus .comprising a chain of dot and dash electromagneticrelaya aplurality -of ysolenoids whoseopchargerdevice circuits for operating a dotrela in said/.chainwhen adot signal is received, means including electronic discharge device circuits for 35 operating afdashrelay in said chain` whena dash signal is received, means responsiveto the'operation of said dot -and dash relays for advaicl iri'gltliefoperationof the relays in said chain, ,electronic discharge device circuits for separat,a

7 5, ing, spacesoi different durations tothereby distinguish between inter-element spaces andfintercharacter' andV interword spaces, connections op,- eratin'g aA selected' solenoid "by said last electronic discharge device circuits at the en'd-of everycharacter signal code combination and'word signal 19 code combination, and means k operative subsequent to theloperation of a selected solenoid for resettingthel chain of relays to normal in readinessfor operation in response to another code combination.

14. Apparatus for converting Morse code signals having mark and space elements for every code combination to other codesignals, including a first self-restoring trigger circuit responsive to `the start of every mark element, a second selfrestoring trigger circuit under control :of said first trigger circuit and responsive to the trailing edge of a mark element whose duration is less than the active time of said first trigger circuit, and a third self-restoring trigger circuit under 'control of said first trigger circuit and responsive to the trailing edge of a mark element whose duration is longer than the active time of said first trigger circuit, a fourth self-restoring trigger circuit having a stable and an active state and which is responsive to the end of a mark element, a fifth self-restoring trigger circuit coupled to and responsive to the restoration of said fourth trigger circuit, v'said fifth trigger circuit having an active time duration which is longer than that of said fourth trigger circuit, and a sixth Aself-.restoring trigger circuit having a pair of input connections extending to the outputs of said fifth trigger circuit for enabling the trip ping of said fifth trigger circuit at both the acti vation and restoration of said fifth trigger circuit, and means to prevent the activation of both said fifth and sixth trigger circuits during the presence of a mark element, a chain of relays under control of said second and third trigger circuits, a stepping relay operating in response to a mark element for advancing the operation of the relays in said chain, a plurality of solenoids whose operating paths are controlled by the setting of said relay chain, an electronic circuit for operating the selected solenoid in response to the tripping of said sixth trigger circuit, said electronic circuit having its current passing condition momentarily altered by the tripping of said sixth trigger circuit, and means responsive to the restoration to normal of the current passing con* dition of said electronic circuit for resetting the chain of relays to normal in readiness for operation in response to another signal code combination.

15. An unequal length code telegraph translator for translating code signals utilizing dot marking elements, dash marking elements and spaces for the code combinations, an electronic circuit operatively responsive to received dot marking elements, an electronic circuit operatively responsive to received dash marking elements, a chain 'of relays under control of said circuits, means responsive to each marking element for advancing the operation of the relays in said chain, one of the relays in said .chain being operative only after the receipt of a predetermined plurality of marking elements, a figure or case shift solenoid, and means operative in response to the operation of said one relay for operating said figure or case shift solenoid.

16. An unequal length code telegraph translator for translating code signals utilizing dot marking elements, dash marking elements and spaces for the code combinations, a circuit responsive to received dot marking elements, a circuit responsive to received dash marking elements, a chain of relays under control of said circuits, means responsive to each marking element for advancing the operation of the relays in said s" lli " mal.

.iii

17. An unequal length code telegraph translator for translating code signals utilizing dot marking elements, dash marking elements and spaces for the code combinations, means including a dot trigger circuit responsive to received dot marking elements, means including a dash trigger circuit responsive to received dash marking elements, a chain of relays under control of said dot and dash trigger circuits, a stepping relay operative at the start of each marking element for advancing the operation of the relays in said chain, one of the relays in said chain being operative after the receipt of a predetermined plurality of marking elements, a case shift relay operative in response to the operation of said one relay in said chain, a figure or 4case shift solenoid, and means for operating said solenoid in response to the operation of said case shift relay.

18. A circuit 'arrangement for discriminating between code elements of different time duration in apparatus for translating code signals, including a flrst self-restoring electron discharge device trigger circuit operatively responsive to the start of every mark element, a second self-restoring electron discharge device trigger circuit coupled to and under control of said first trigger circuit and operatively responsive to the trailing edge of a mark element whose duration is 1ess than the active time of said first trigger circuit, and a third self-restoring electron discharge device trigger circuit under control of said first trigger circuit and operatively responsive to the trailing edge of a mark element whose duration is longer than the active time of said first trigger circuit, each of said trigger circuits comprising a pair of electrode structures having anode and grid electrodes and cross-connections interconnecting the grid and anode electrodes regeneratively, and resistor and condenser elements of predetermined values in circuit with said electrodes for determining the active time of the trigger circuit.

19. In combination, a first self-restoring trig-Y ger circuit comprising a pair of vacuum tubes having anode and grid electrodes cross-coupled regeneratively, an electron discharge device having a grid connected over a direct current path to the anode of one tube of said lpair and having a cathode coupled to ground through a condenser shunted by a rectifier, another electron discharge device having a grid connected over a different direct current path to the anode of said other tube of sfaid pair and having a cathode coupled to ground through a condenser shunted by a rectiiler, second and third self-restoring trigger circuits coupled to different cathodes of said electron discharge devices, a pulse input circuit, means including a dilerentiator circuit vcoupled to said input circuit for supplying to said first trigger circuit impulses of such polarity and magnitude as to trip said first trigger circuit at the start of a pulse in said input circuit, and additional individual difierentiator circuits coupling said input circuit to said second and third self-restoring trigger circuits for supplying tripping impulses 21 thereto at the endof a pulse in said input circuit.

20. A circuit arrangement for discriminating between characters of prearranged code signals differing in the total number of individual marking elements, comprising a first solenoid to be cperated upon receipt of characters having less than a predetermined number of individual marking elements, a second solenoid to be operated upon receipt of characters having said predetermined number of individual marking elements, means to actuate said second solenoid upon receipt oi a marking element of ordinal number equal to said given number of the code character under consideration, and means responsive to the rst marking element in the succeeding code character to actuate said first solenoid.

21. A circuit arrangement for discriminating between characters of prearranged code signals differing in the total number of individual marking elements, comprising a first solenoid to be operated upon receipt of characters having less than a predetermined number of individual marking elements, a second solenoid to be operated upon receipt of characters having said predetermined number of individual marking elements, a relay chain arranged for successive operation of the relays therein upon receipt of the individual marking elements of the character under consideration, a shift relay responsive to the relay in REFERENCES CITED The following references are of record in the file of this patent:

'UNITED STATES PATENTS Number Name Date 1,805,114 Tevis May 12, 1931 2,094,733 Byrnes Oct. 5, 1937 2,289,987 Norton July 14, 1942 2,289,988 Norton July 14, 1942 2,384,513 Winter Sept. 11, 1945 2,418,521 Norton et al Apr. 8, 1947 2,425,063 Kahn et al. Aug. 5, 1947 2,429,500 Wolfner, 2d Oct. 21, 1947 OTHER REFERENCES American Standard Denitions of Electrical Terms. A. I. E. E., 1941 (page 229, 65.65.500). 

